Mechanism of the External Short Circuit Induced Internal Short Circuit in Liquid Metal Batteries

Battery technology is pivotal in large-scale energy storage systems, valued for its flexibility and high efficiency. Among various options, liquid metal batteries (LMBs) stand out with promising applications in the energy storage field, thanks to their low cost, long lifespan, high safety, and large capacity. External short circuits (ESC), as a common form of abuse, can potentially lead to more severe internal short circuits (ISC). However, most existing research on LMB has not thoroughly addressed the underlying trigger mechanism. In this paper, the trigger mechanism is revealed through the electrode morphology analysis and proved by the multiphysics model simulation. In the ESC process, the irregular lithium deposition is induced by the uneven current density, which finally leads to the contact between the anode and cathode, that is, ISC. The ISC is most likely to occur at the center of the cathode or near its junction with the cathode shell. The insights gained from this study may be of assistance to improve the configuration design of LMB and reduce the risk of short circuits occurring in the application.